Hypothesis Writing Worksheet

Name:

Date:

📚 Part 1: Understanding Hypotheses

1. Which sentence is a testable scientific hypothesis?

The school should be painted a different colour to look nicer.

If plants receive blue light, then they will grow taller than plants receiving red light.

Chocolate tastes better than vanilla for most people.

2. Which option names the independent variable (IV) in this hypothesis: "If water temperature is increased, then the speed of a chemical reaction will increase."

The speed of the chemical reaction

The amount of chemical used

The water temperature

3. Check all characteristics of a good scientific hypothesis:

Testable by experiment or observation

Based on a value judgement (good/bad)

Predicts a clear relationship between variables

Uses vague words like "might" without measurable terms

4. Which is the best prediction from the hypothesis "If the mass of a toy car increases, then its speed down a ramp will decrease"?

Heavier cars may be slower.

If mass increases by 100 g, then average speed down a 2 metre ramp will decrease by about 0.2 m/s.

Cars behave differently on ramps.

✏️ Part 2: Write and Refine Hypotheses

5. Write a clear, testable hypothesis for this question: "Does the colour of light affect plant growth?"

6. For your hypothesis above, list the Independent Variable (IV), Dependent Variable (DV) and one Controlled Variable.

IV: _______________________________________________

DV: _______________________________________________

Controlled variable: _________________________________

7. Rewrite your hypothesis as an "If... then..." statement (concise):

8. Briefly describe one simple experiment (step and one measurement) that would test your hypothesis. Include units where appropriate (e.g., cm, °C, g).